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Fluid-Soil-Structure interaction in liquefaction around coastal structures. WP2. Pierre Foray – David Bonjean Hervé Michallet INPG. Plan. Introduction Experimental Set-up Transducers accuracy analysis Experimental results Conclusion / Perspectives. Introduction. Methodology.
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Fluid-Soil-Structure interaction in liquefaction around coastal structures WP2 Pierre Foray – David Bonjean Hervé Michallet INPG
Plan • Introduction • Experimental Set-up • Transducers accuracy analysis • Experimental results • Conclusion / Perspectives
Methodology • Physical modelling of the wave action on a pipe partly buried or resting on the seabed • Full scale modelling of the pipe • Wave action simulated by a mechanical cyclic loading • Emphasis in accurate pore pressure measurements • Link with cyclic undrained/partially drained behaviour of sands
Seabed physical model Medium to fine Fontainebleau sand (d25 = 0,25 mm) Dry pluviation system, controlled falling height Low uplift hydraulic gradient
Hydrodynamic forces model Trolley supporting the pipe Horizontal electric actuator horizontal cyclic efforts on the trolley Vertical pneumatic actuator weight of a real pipe & lift effect
Transducers accuracy analysis Questions : * Influence of the porous stone * Air bubbles apparitions ?
Influence of desaturation on pore pressure transducer response time
Pipe displacement :dense sand,Fhmax = 50 daN, period = 2s,160 cycles.
Compared Total/Pore pressure recordings (30°)Fhmax = 50 daN, period = 2s
Peaks in Pore pressure recordings (30°)Fhmax = 50 daN, period = 2s
Conclusion / Perspectives Parametric study : sand density, period, Fhmax. Video image processing : displacement & velocity fields. The PANDA